.nav{width:100%; position:fixed;top:0;left:0; z-index:99; }
.nav--drak{background:transparent; border-bottom:0;}
.nav--light{background:#fff; border-bottom:1px solid #e8eaec;}

.nav .arrow{width:6.4rem;height:0.6rem;  margin:0 auto;text-align: center;font-weight: bold; line-height: 0.6rem}

.nav .arrow div{width:0.29rem;height:0.6rem; background-size:100%;float: left;margin-left: 10px;}
.nav .arrow img{float:left;padding-top:0.15rem;width:0.29rem;height:0.31rem; background-size:100%;float: left;margin-left: 10px;}

/*.nav .arrow div.gray{background-image:url(./assets/images/history1.png) }*/
/*.nav .arrow div.default{background-image:url(./assets/images/history.png) }*/